Context: Urine lactate may be a novel biomarker of lactate production capacity but its reliability has been unsatisfactory so far.
Objective: To compare the reliability of urine lactate between controlled hydration and no hydration after maximal exercise.
Material and methods: Athletes performed swimming exercise four times: two followed by consumption of 1 L of water and two followed by no water intake. Blood and urine lactate was measured.
Results: The reliability of urine lactate was good and similar to that in blood only after controlled hydration. Blood and urine lactate were correlated under both hydration conditions.
Discussion and conclusion: Controlled hydration after exercise provides satisfactory reliability of urine lactate.
Keywords: Anaerobic lactic capacity; blood glucose; blood lactate; exercise metabolism; hydration; intraclass correlation coefficient; reliability; swimming; urine lactate.